dnsedit

The DNS filter performs a lookup (either an A record/CNAME record lookup or a reverse lookup at the PTR record) on records specified under the reverse and resolve arrays.

The config should look like this:

filter {
  dns {
    type => 'type'
    reverse => [ "source_host", "field_with_address" ]
    resolve => [ "field_with_fqdn" ]
    action => "replace"
  }
}

This filter, like all filters, only processes 1 event at a time, so the use of this plugin can significantly slow down your pipeline’s throughput if you have a high latency network. By way of example, if each DNS lookup takes 2 milliseconds, the maximum throughput you can achieve with a single filter worker is 500 events per second (1000 milliseconds / 2 milliseconds).

 

Synopsisedit

This plugin supports the following configuration options:

Required configuration options:

dns {
}

Available configuration options:

Detailsedit

 

actionedit

  • Value can be any of: append, replace
  • Default value is "append"

Determine what action to do: append or replace the values in the fields specified under reverse and resolve.

add_fieldedit

  • Value type is hash
  • Default value is {}

If this filter is successful, add any arbitrary fields to this event. Field names can be dynamic and include parts of the event using the %{field}.

Example:

filter {
  dns {
    add_field => { "foo_%{somefield}" => "Hello world, from %{host}" }
  }
}
# You can also add multiple fields at once:
filter {
  dns {
    add_field => {
      "foo_%{somefield}" => "Hello world, from %{host}"
      "new_field" => "new_static_value"
    }
  }
}

If the event has field "somefield" == "hello" this filter, on success, would add field foo_hello if it is present, with the value above and the %{host} piece replaced with that value from the event. The second example would also add a hardcoded field.

add_tagedit

  • Value type is array
  • Default value is []

If this filter is successful, add arbitrary tags to the event. Tags can be dynamic and include parts of the event using the %{field} syntax.

Example:

filter {
  dns {
    add_tag => [ "foo_%{somefield}" ]
  }
}
# You can also add multiple tags at once:
filter {
  dns {
    add_tag => [ "foo_%{somefield}", "taggedy_tag"]
  }
}

If the event has field "somefield" == "hello" this filter, on success, would add a tag foo_hello (and the second example would of course add a taggedy_tag tag).

failed_cache_sizeedit

  • Value type is number
  • Default value is 0

cache size for failed requests

failed_cache_ttledit

  • Value type is number
  • Default value is 5

how long to cache failed requests (in seconds)

hit_cache_sizeedit

  • Value type is number
  • Default value is 0

set the size of cache for successful requests

hit_cache_ttledit

  • Value type is number
  • Default value is 60

how long to cache successful requests (in seconds)

max_retriesedit

  • Value type is number
  • Default value is 2

number of times to retry a failed resolve/reverse

nameserveredit

  • Value type is array
  • There is no default value for this setting.

Use custom nameserver(s). For example: ["8.8.8.8", "8.8.4.4"]

periodic_flushedit

  • Value type is boolean
  • Default value is false

Call the filter flush method at regular interval. Optional.

remove_fieldedit

  • Value type is array
  • Default value is []

If this filter is successful, remove arbitrary fields from this event. Example:

filter {
  dns {
    remove_field => [ "foo_%{somefield}" ]
  }
}
# You can also remove multiple fields at once:
filter {
  dns {
    remove_field => [ "foo_%{somefield}", "my_extraneous_field" ]
  }
}

If the event has field "somefield" == "hello" this filter, on success, would remove the field with name foo_hello if it is present. The second example would remove an additional, non-dynamic field.

remove_tagedit

  • Value type is array
  • Default value is []

If this filter is successful, remove arbitrary tags from the event. Tags can be dynamic and include parts of the event using the %{field} syntax.

Example:

filter {
  dns {
    remove_tag => [ "foo_%{somefield}" ]
  }
}
# You can also remove multiple tags at once:
filter {
  dns {
    remove_tag => [ "foo_%{somefield}", "sad_unwanted_tag"]
  }
}

If the event has field "somefield" == "hello" this filter, on success, would remove the tag foo_hello if it is present. The second example would remove a sad, unwanted tag as well.

resolveedit

  • Value type is array
  • There is no default value for this setting.

Forward resolve one or more fields.

reverseedit

  • Value type is array
  • There is no default value for this setting.

TODO(sissel): The timeout limitation does seem to be fixed in here: http://redmine.ruby-lang.org/issues/5100 # but isn’t currently in JRuby. TODO(sissel): make action required? This was always the intent, but it due to a typo it was never enforced. Thus the default behavior in past versions was append by accident. Reverse resolve one or more fields.

timeoutedit

  • Value type is number
  • Default value is 0.5

resolv calls will be wrapped in a timeout instance